Digital Compass

Like the mouse trap, the needle compass is so simple that it seems perfect. The only working part is a magnetized needle surrounded by liquid. Even the liquid is not necessary because its only purpose is to slow down the needle. For a long time, there was nothing that could find magnetic north other than a needle compass, but that all changed with the advent of digital technology. The digital compass is one of the most significant innovations in navigation since the chronometer. It may not be as important as the Global Positioning System (GPS) but it is still a great invention.

The needle compass has not changed much since it first appeared thousands of years ago. Even today, it is a very simple and effective device, and you would have to be a genius to make it any simpler. The only real problems with the needle compass are its slow speed and sensitivity to movement. Waiting for the needle to settle down seems to take forever, especially when you need to get a bearing in a hurry. Even worse, the slightest bump moves the needle and you have to wait for it to settle again. A digital compass avoids these two problems by not using a needle or any other moving parts.

On the outside, a digital compass may look like a regular digital watch, but that simplicity belies the complex technology on the inside. It uses solid-state electronic components that are powered by a small battery. Just like a wrist watch, it uses very little power and can potentially work for many years on a single battery. The components that detect the Earth’s magnetic field are called magnetometers, several of which are needed to calculate a bearing. An small LCD display is used to show the bearing, along with other functions the digital compass might have, such as the time and date.

A digital compass is more precise than reading a bearing from the dial of a needle compass. There is even a hold button that freezes the bearing so you do not have to move your eye away from the sight to read the bearing. By reading the bearing rather than trying to remember it, there is less chance of making an error when plotting a course on a chart. When the hold button is pressed again, normal compass function is returned. It will even go into power saving mode after a few minutes of inactivity. Just like a needle compass, you need to keep a digital compass away from any large objects made from ferrous metals, otherwise the bearing will be affected by their magnetic fields.

When choosing a digital compass, look for one that has a large LCD screen with a strong backlight. It should be viewable in all lighting conditions, even in the pitch darkness of a moonless night. To survive in a marine environment, a digital compass needs to be water resistant. Even better, choose a model that floats in the water, so that it can be retrieved if it happens to get dropped overboard. The advanced models have declination adjustment which lets you correct for magnetic variation. Other features that a digital compass may have include a clock with alarm function, calendar, stop watch, and thermometer. Be sure that it also comes with a lanyard and carry case.

It is hard to say whether the digital compass will continue to exist as a separate device for much longer. Every year, there is some new gadget that does the same job as several other gadgets and usually costs less to buy. Digital compass sales are already suffering from the growing popularity of mobile phones, satnavs, and other GPS receivers. Along with many other features, these gadgets are also capable of showing a compass bearing. This is great news for bushwalkers and sailors who prefer not to carry around too many electronic gadgets in their pockets.

This Digital Compass Review is Written/Updated
on Feb 1st, 2011 and filed under Consumer Electronics.
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